Schema(JSON)^js

A JavaScript Schema class that implements the JSON Schema specification as immutable objects with lazy, async initialization. The class creates optimized validations using closures and thunks. It currently supports the draft-04 and draft-06 versions of the JSON Schema specification.

Motivations behind the project:

• implement a JSON Schema validator leveraging modern JS features
• implement as instances of a class so the schema can be referenced in code
• include support for synchronous or asynchronous validations
• allow for partial validations for complex object properties
• small and lightweight with no dependencies
• universal support for the latest browsers and Node.js
• fastest JSON Schema validator without code generation

Contents

• Installing
• Examples
• API
• Environments
• Benchmarks
• Future
• Contributing
• Changelog

Installing

Install using npm:

npm install --save schema-json-js

Examples

Below are numerous examples on how to use the Schema class.

Initialized immediately

• An example Schema initialized immediately.

  // ...
  const schema = await new Schema({}) // immediately immutable
  // ...
  schema.validate('something')
  // ...
  

• An example Schema initialized immediately with cached JSON Schema references defined.

  // ...
  const REFS = {
    'https://localhost/schema': {}
  }
  const schema = await new Schema({ $ref: 'https://localhost/schema' }, REFS) // immediately immutable
  // ...
  schema.validate('something')
  // ...
  

• An example Schema initialized immediately with async validation.

  // ...
  const schema = await new Schema({}, true) // immediately immutable
  // ...
  await schema.validate('something')
  // ...
  

• An example Schema initialized immediately with cached JSON Schema references defined and async validation.

  // ...
  const REFS = {
    'https://localhost/schema': {}
  }
  const schema = await new Schema({ $ref: 'https://localhost/schema' }, REFS, true) // immediately immutable
  // ...
  await schema.validate('something')
  // ...
  

Initialized lazily

• An example Schema initialized lazily.

  // ...
  const schema = await new Schema() // not immutable yet...
  // ...
  await schema.assign({}) // now it's immutable
  // ...
  schema.validate('something')
  // ...
  

• An example Schema initialized lazily with cached JSON Schema references defined.

  // ...
  const schema = await new Schema() // not immutable yet...
  // ...
  const REFS = {
    'https://localhost/schema': {}
  }
  await schema.assign({ $ref: 'https://localhost/schema' }, REFS) // now it's immutable
  // ...
  schema.validate('something')
  // ...
  

• An example Schema initialized lazily with async validation.

  // ...
  const schema = await new Schema(true) // not immutable yet...
  // ...
  await schema.assign({}) // now it's immutable
  // ...
  await schema.validate('something')
  // ...
  

API

• Schema

Environments

• All modern browsers and Node 10+ without polyfills.
• The build script is currently set to ECMA 9.

Benchmarks

There is a small benchmark to showcase our performance against some similar solutions. One of the many ways schema-json-js stands apart from many other validators is its ability to perform partial schema validation.

• Node.js
  • as cached Schema instance
  • as serialized Schema instance
• Browsers
  • Chrome
    • as cached Schema instance
    • as serialized Schema instance
  • Firefox
    • as cached Schema instance
    • as serialized Schema instance

Future

• create contributing guide
• implement support for the draft-07 and 2019-09 JSON Schema specification
• feature requests via issues

Contributing

We are currently drafting our contributing guide in the new monorepo!

Changelog